1. Field of the Invention
The present invention relates to a content playing system that includes a playing terminal which retrieves and plays desired content data such as music and moving pictures, the content data having been purchased from e.g. content providers by the user of the playing terminal and stored in a user's content server at home. The present invention particularly relates to the content playing system that prevents content data from being copied to another playing terminal owned by a third party.
2. Description of the Background Art
Content playing systems which includes a playing terminal have been known recently, in which the playing terminal retrieves and plays desired content data such as music and moving pictures, the content data having been purchased from e.g. content providers by the user of the playing terminal and stored in a user's content server at home. For example, Japanese patent laid-open publication No. 2004-37981 discloses a content playing system for playing music content data to listen to by a driver in a car. Such content data is retrieved from a content server by the driver at home and played by a playing terminal mounted in the car.
As to the playing terminals, ipod (registered trademark of Apple Computer, Inc.), for example, has been known for storing desired content data such as music and moving pictures in its memory to enjoy contents in the open air. This explanation is based on the product information of the iPod presented as of Nov. 29, 2005 on the website on the URL:http://www.apple.com/ipod/ipod.html.
Furthermore, streaming distribution technologies have also been known for playing content data, e.g. music and moving pictures, over a telecommunications network, such as the Internet. In these technologies, a content is sequentially played while its content data is continuously received.
However, these content playing systems are subjected to a problem that, once the content data such as music and moving pictures purchased from e.g. content providers are copied on the memory of the content server, the content data can be transmitted easily from this content server to another which is owned by a third party. Therefore the copyright of the content data could be infringed.
Furthermore, the conventional playing terminals have a difficulty in the physical or storage size thereof. In order to store the large volume of content data such as moving pictures, the playing terminals are required to have large storage capacity, thus the terminals becoming larger in size.